1. Field of the Invention
The present invention relates to a method for detecting filter clogging, an apparatus for monitoring filter clogging and bed-side system, more particularly the present invention relates to a method for detecting filter clogging used in a blood purifying system, an apparatus for monitoring filter clogging on the basis of the filter clogging, and a bed-side system having the apparatus.
2. Description of Related Art
A blood purification method is roughly classified into two types. One is a type that removes substances in the blood through transfer (diffusion or filtering) to a waste liquid or adsorption into a membrane when the blood flows in a hollow-fiber of a filter, and hemodialysis, hemofiltering, hemodiafiltering, plasma exchange, double filtering plasmapheresis, plasmapheresis are some examples of this type. The other is a type that removes substances in the blood through adsorption into an adsorbent in a filter when the blood passes through the adsorbent (cloth, bead, etc.), and blood adsorption is an example of this type.
The former type of blood purification method requires a filter for dialyzing or filtering the blood. The clogging of the filter is prevented from occurring by using an anti-coagulant or adjusting a flow rate at medical sites.
As a method of optimizing a filter flow rate using filter pressure information, for example, Patent Document 1 discloses a control system using the trans-membrane pressure (TMP). Patent Document 2 discloses a dialysis therapy apparatus provided with a device for monitoring removal of an injection needle which serves as an inlet and outlet of the blood, by monitoring pressure information, particularly, pressure pulsing information in a dialyzing fluid path.
Further, Non-Patent Document 1 discloses a method of calculating an internal filtering flow rate using a result of Fast Fourier Transform of the pressure in frequency analysis to monitor the filtering efficiency in filtering dialysis using a membrane with high water permeability (JP05-508584, JP11-104233, and Journal of Japanese Society for Dialysis Therapy, Vol. 35, The Japanese Society for Dialysis Therapy, page 616 “WS14-6”, Jun. 20, 2002).
However, overdosage of an anti-coagulant in an attempt to prevent clogging of a filter may cause a danger of producing serious hemorrhagic complications (cerebral hemorrhage, etc.).
Further, there is an economical problem because the anti-coagulant is expensive.
Therefore, it is desirable to detect the clogging of a filter early, adjust a dosage amount of the anti-coagulant properly and control the flow rate to prevent the clogging from developing.
In view of the foregoing, it is an object of the present invention to provide a method for detecting filter clogging, an apparatus for monitoring filter clogging on the basis of the filter clogging and bed-side system having the apparatus which are able to keep track of the filter clogging with precision and in detail.